In U.S. Pat. No. 4,388,159, K. F. Dockus et al. disclose a complex surface preparation treatment of the surfaces of aluminium and aluminium alloy articles, in particular aluminium-silicon alloys prior to plating a nickel or nickel-lead layer for brazing, the treatment comprising the steps of abrading the surface with a low-density abrasive product comprising a plurality of flexible, tough fibrous members intertwined and bonded together and having abrasive granules randomly distributed throughout and bonded thereto, in the presence of an C1-C4 alcohol, preferably isopronanol.
In U.S. Pat. No. 4,097,342, W. E. Cooke et al. disclose an electrolytic cleaning treatment which involves subjecting aluminium strip to direct current (“d.c.”) anodising for a few seconds at high temperature, preferably more than 80° C., and current density in a concentrated strong mineral acid electrolyte.